International Journal of Cardiology 188 (2015) 34
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
The role of thyroid in Takotsubo cardiomyopathy Sourabh Aggarwal a,⁎, Ravikanth Papani b, Vishal Gupta c,d a
Department of Internal Medicine, Western Michigan University School of Medicine, Kalamazoo, MI, United States Department of Pulmonary and Critical Care Medicine, University of Texas Medical Branch, Galveston, TX, United States c Cardiovascular Research Institute, Kalamazoo, MI, United States d Echo Lab, Borgess Cardiology Institute, Kalamazoo, MI, United States b
a r t i c l e
i n f o
Article history: Received 26 March 2015 Accepted 28 March 2015 Available online 30 March 2015 Keywords: Takotsubo cardiomyopathy Thyroid pathology Levothyroxine Hypothyroid Autonomic nervous system
On sub-analysis of our data, out of 27 patients who had a known history of hypothyroidism, a thyroid proﬁle was available for 20 patients and 3 of them were hyperthyroid (based on low TSH and/or high free T4/T3). In other 51 patients, who did not have a known history of hypothyroidism, a thyroid proﬁle was available for 24 patients and 2 of them were found to be hyperthyroid. It's still unclear to us why these mostly elderly females with history of hypothyroidism are predisposed to Takotsubo cardiomyopathy. An altered autoimmune nervous system in hypothyroid patients, the hyperadrenergic state due to hypothyroidism and reduced estrogen in post-menopausal females might have roles to play in it. But it's important to realize that our study only shows an association of thyroid pathology, albeit a signiﬁcant association and it needs to be conﬁrmed with multi-centric prospective study. We are already doing a larger study based on a national database to deﬁne the association between thyroid pathology and Takotsubo cardiomyopathy.
To the Editor,
Conﬂicts of interest
We thank Dr Madias for his interest and comments on our recent paper [1,2]. It is indeed interesting to ﬁnd such high prevalence of thyroid pathology (hypothyroid patients on levothyroxine therapy) in patients with Takotsubo cardiomyopathy. The data was collected by chart reviews so the availability of data for analysis was limited by the retrospective nature of the study and thyroid studies were not available for other 34 patients. However, our patient population (predominantly elderly female) was comparable to other studies on Takotsubo cardiomyopathy and similar distribution has also been shown by us in a separate analysis of nationwide data . We have also previously reported a case of patient with recurrent Takotsubo cardiomyopathy who had a history of hypothyroidism, was on levothyroxine replacement and was found to be in the hyperthyroid state during both episodes with a normal thyroid proﬁle in the intervening period .
The authors report no relationships that could be construed as a conﬂict of interest.
⁎ Corresponding author at: Western Michigan University School of Medicine, 1000 Oakland Drive, Kalamazoo, MI 49008, United States.
http://dx.doi.org/10.1016/j.ijcard.2015.03.402 0167-5273/© 2015 Published by Elsevier Ireland Ltd.
References  S. Aggarwal, R. Papani, V. Gupta, Can thyroid break your heart? Role of thyroid in Takotsubo cardiomyopathy: a single center retrospective study, Int. J. Cardiol. 184 (Feb 25 2015) 545–546, http://dx.doi.org/10.1016/j.ijcard.2015.02.058 ([Epub ahead of print]).  J.E. Madias, Is hypothyroidism (on levothyroxine replacement) a precipitant of Takotsubo syndrome? Int. J. Cardiol. 187 (2015) 29–30.  S. Aggarwal, V. Gupta, Epidemiology of Takotsubo cardiomyopathy in US: an analysis of NIS data, J. Am. Coll. Cardiol. 65 (10_S) (2015).  R. Papani, S. Aggarwal, V. Gupta, Thyroid broke my heart twice! A case report of recurrent Takotsubo cardiomyopathyAvailable from http://med.wmich.edu/sites/ default/ﬁles/2013%20full%20program.pdf (Accessed on 3/25/2015).